SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a742ecae224f179bfb450929c758f081769f6ebdb37fcd8f3f2d4fbe231b5d5' 
  AND token = 'jgwfCXgy1TXrBaCt0hqnUmn2tKvvpd6y+ofButHbAp0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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