SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5774a90ee3357ad920eac02b656c5b43fd39dd3fc739ea4b25bcb0235b3e86ea' 
  AND token = 'QZctRPvk3LkR1kwvjS5p9OJCkDuesmrECawouBIQeKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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