SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'afb7d02e0d21e3fd10c39b57a6e573b19cd08a5bb5ff83323495133ea5102e19' 
  AND token = 'kEMYZGZGadSguTDCQCrPXuhOiHH8kkMOBgIxLA6ZE4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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