SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7314955952f748959d4e774e03166b5bdd1d9ff4f68293fd000267e23ffaf3e5' 
  AND token = '+9QO1XnFscfouErPNdAqjuSEozr23+KEyMfCBxBDBtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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