SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74871cff5547bc21e4de97e0ec3cf40cf9c03620fd9dbf837b6f8e9093c832ff' 
  AND token = '0WxwXgaDsFzqH2urNwS9iI+hheK+2MXxVb3ZLa/pUPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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