SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '772b36310737dcdb76814041e4d34e76abdc3741f9ae3afa0360c459f126379d' 
  AND token = 'BwqTjdiYgtePzVzXCMsK5pgNm99D21z7RBi/hGpfphI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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