SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ffe2ee1d01d4ff7181b692e9600928a450b12b6d17df4f9648a965b196165c53' 
  AND token = 'DegcpBhPKMPqvSzeS0x4VxM3HB9iXevvXv1lCBbaYZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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