SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecb1220381a8829eec1f65891ab060374f932716737edab86c977c22a4e6bb5a' 
  AND token = 'xYXK5gO1iX5ydtLvmaDTJUdL5vsYQsjO22myzhFJWqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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