SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9e60ca2cab7964824119958b92fed8fd3a93cb3c57b56226e1a3eef8528b3e7' 
  AND token = 'LH4V1rtJKfFPtWFZMnpNBKNxv1Ux4dveUhKgxhB3lUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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