SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '852e550de77930c32c65dcaf05d0fb603cf2c811d74ce6b6ff18dc36669c96e4' 
  AND token = 'CMHnsdBrlxIZqbOFDkVtRu8CPfaoHfIByg6clJNT2vg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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