SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3787d4ca7e96516e6689acf3043af8ce1a8a08bfcb5ba7e80c99105bd4676729' 
  AND token = 'pL/WR1FNCnKwXoDRy/UR/MZJ34PpDRYwT9jXwVPwthI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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