SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c41a30dbdad80516b511095daef7b43f65ebececaa1aa296988cf6417abeace7' 
  AND token = 'H1b2jzVs3igHsLE3QCUwPd0apyoMv2HRdx0X/SneXf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}