SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f8d30257849164122249977810bd4afd37286040c40db65738a0767e00ce14c' 
  AND token = 'Fhbjm4KNJimRhU9S/xL6Ph5myhBzjDA+OL2fRUFZS+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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