SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba771897ef2c67370fdaa7455102013bc63678d457d437d884b6b0018b46ddec' 
  AND token = 'qwlbjNRsrauZQ6WV5gqxDU31fwUynvk4zl+JKBM6JyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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