SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a404fc0fb999fca4e61e34a421a0290e165c3df52191eea32639795e589b9d5' 
  AND token = 'HHp21Ub40ZCwu8FK7e4iSUqATM6SsqeDqSW52majxJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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