SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '72d9a7f457af0024a583700e21ca4fa3b681c3dc31c16b1aeb3e49818dbe2044' 
  AND token = '8jspxtG/ALK5d9zcHyXlv9tKQ/mTkOETGr/XSrD5PCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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