SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4052e50d0f75dc65a29af5027e43cc4d83ee965185266c5bcc3150584aafeb86' 
  AND token = 'EYUX7PRaSucypNW5qDvhwtA2XjWYJXqBwBxvjC7xvko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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