SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9da58896138f947a368dfd2cbcecc7fbd5cab8c177b4889a9423c61dd6acf66' 
  AND token = 'vsVpu6hElyB0zdPXfPHnJVwYQ2MRhDXZxh94Wdl032c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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