SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '982314702629c77b1b8ee8dd5669003e8712a0a6b0849a24707f63a902c026e6' 
  AND token = 'MMau0ohczInmEN+kOfodXWVCBluWpEvy/12cOr9prDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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