SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dca9dd760d8b58086dfab3db7971263ebcb56cd22adfdc17a5df2f5f38556f79' 
  AND token = 'I8ctoqwMAAsUui6oCtT0LCP3iSlPOXCK83IpejV3fqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}