SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f8b756ec6310cbb1fdc0304b0e00faa3407a23b2264e85213258a2f71651d9a7' 
  AND token = 'Cqx6dr5tTMlsXiafPgmwfBhmYlYKp9gLw/S8nQUzPi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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