SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f31b5792752ccf1a28d4e6285ccb85d4f18517bd6c2c45a433f608da0167da10' 
  AND token = 'IuALe8bSIXjdSZFXqTrPr+yf41ENxJcn3OGv/2BrLvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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