SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ac82dfd7a17f31faada9afd1a0dd3fa8af30aace8f49f46587262906bfc168f2' 
  AND token = '/47rIAGLe7VFg4aUA3Hn//LVaN7AZn9aKGeWI8iRFzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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