SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce71b8cf43af2635a17f0beb676162e8f1e74fb6bf9a569c58e927a29afdeade' 
  AND token = 'YDnHs8cZck/+EwtIMnjHoaEu8mKRL5gBR/lM/PXBAd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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