SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd3a995a80794c90d4d88e29db3937860b6570a63f1a1f6128da5c5bb1c82602' 
  AND token = 'ZTI6PIgMHZNGB6wRJJ7j3aDaq/2u+j8I+Lx0gbvLQYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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