SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c5db946515efaf5262f12c4f9ecee19c24245fe4047fab2c6d4109ad20bf39f7' 
  AND token = 'BI97vEz71kOvQVK0crL+qh27BvDMrQpuIvvUFUeS/mw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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