SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e1ea6bc1bb1bb70b99f1bf656a4136e26a700972a5a129a316487667d2d41e0' 
  AND token = '0yq6qg+twW9t40FAcxfiEOi6R0zNrdULTzMueZKPsAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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