SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e834985082d73ad23d7ca2f79607700930a1dd32995b16c1ddafc75b3934c3e' 
  AND token = 'ngynUHFf91PwhRbrBr6DItZRZ9LhjobKz8fFPC+jQ1M=' 
  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"
    }
  }
}