SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fdff6e18a17926619aef849843822030051dc7b54b04579609613b8180df5f87' 
  AND token = 'Yr+7vGXJOkSCkWzkEYLRqmb76mKcCwqR/p01X7OXR3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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