SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c0a052692a32ee2c74031d6676959630216afcd51dda274ebba160c898da563f' 
  AND token = 'FgcgOCe5qzr8U3vTDcMAJRykztuc151sUwccCss+d9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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