SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7028ba21b79be1a623795f7cf3543cec198b0d354b2f0de4443b31c4d4584e86' 
  AND token = 'TV4VDPHkDwOzOHr0+TlYgF/4Hp4FTXL3Jo7SCPq9c0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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