SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdb6ce855425437f92dcc1560c0665e27623a37221edfa0b42c2de56345b08b4' 
  AND token = 'xlCmurIbMuKJo4evPLcs+bo4QY1wkLCp0X39N5y9c60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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