SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2f8a00e2c60e9d51f9f58e243fc361eb62cef2b91f38b89bbfdf17332c65356' 
  AND token = 'S0BzxO4du6xVGSTIupTEAeodbgVlYnTWWS6y5Y/sm4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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