SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85235155d95d183618c58b42323d89bef01dffb9cdd972af147f8f898a7ac268' 
  AND token = 'JQnaDkEd6UBZtVsnfwxgS/sB46nlRvHm1WALz0+SI7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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