SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dde02b6b3fac5a9d12c294e32926a0c97a731da5a57df73578cebdf04e86eda' 
  AND token = 'h0A/hz49Q4qw+D8lJlX+jK3PwQ1+EgmGDhNDPDVA4yQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}