SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8699d4672d2150a5a7efee08deafc8b655f53530a8b27c9dba4da517c1ce9a0b' 
  AND token = 'RV+UrslN+zB/XxqL5wEMXUAQfoZwq6vsMbr62FsdCuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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