SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '446495c55c9a33b082a08643a448653fe347f126c54d7089708f8a927a351e62' 
  AND token = 'BOqE6t/VhSrw9Zo0cp7YgLgFq2i5BBoAQmfEUTxfG7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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