SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4d379eebd4752f51da4204c5feeaec58dc988a05d223dee2d0dd8565aa640815' 
  AND token = 'ItKJXXs1QtVUHowPPhcFXnVRfyJS/tkquWKl8hHCQfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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