SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22e1504967ad705418a19fd699e7a6ac6ca345e798f3d9aaeb84fb661b33a9c8' 
  AND token = 'clvaNEI3wEVnthbzjTlltZ04OL31gTyjMQ/FYJWdqIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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