SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99c01d272ab16b3cfcce1bf037b1c0d35eb21c1b909021b80a38c98bdf16f690' 
  AND token = 'JK4WDrq0UynB56ZpdI0hvmd+HBAy3Ktksj/ekycr9Y8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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