SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ba0931641339e60f22287044dc0a9a6189a3692a9013cfd2fdb06005795f8232' 
  AND token = '983hPhm3TsUCx35wnZ/itMoRAQvEjq0lMOXmvmI+zaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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