SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a2f03d6eab596d5c21098deb16699811a77e04b031c10fd4925c46c1f5f32083' 
  AND token = 'QBeE4G28DneLp2MSVMEOmEcnRuRWRqifzfntA+dAvh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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