SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fd16da40248006d45b5e84d145d662c1a9d121a6fed3b3bcc64f96d8abf0127' 
  AND token = 'ktqicB68YRmnw33eeJTr8uAPX/NdL0Zq1PsNYbnaWm8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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