SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48e860fe826cd3de9c791028f5a71f98444c8838178d8d10e08a7bb7eb60853d' 
  AND token = 'lDru3vCyaJsFIn3kNRBFYBfJWSEwsXRyYfcGn1pI3dU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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