SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6d8d83701bffac2e5d2e29a121dbe2084fa11e52a827ee5a017dd0062b006bfc' 
  AND token = 'le+tMsl83gPxP35BDc1FCvMCn9azkfl/EKjPMoejJec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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