SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '554674883b5e9f7872e9d1acc5ed5f4fe52a2b7c0e14d186a1d88797ae4f812c' 
  AND token = 'X/Q1zYCmbVJzK6i9G9JgBtjnrhWVV23Te/bJJFLtAEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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