SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f9fd1028cacd2b42b584d86460b62ebf0e366514318ce3921f98adf154bd4f3' 
  AND token = 'Q803OnHswKbpRKKJvhmjFq+gRCe+cRFui3TB5t2QIgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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