SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73052d12c9cd92c399bc71f38d73644f774538270b5b61ed47576c174ab2791b' 
  AND token = 'npwAX2YqPppP7EKolbU4RD66jpZCit21uhmwksXoqvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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