SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2cb81939a3fac14ec857d31a120e5b95f5672ab822e10ed64b48b294acc1a09' 
  AND token = 'vGKFruXfOYq0y/gB3qf7L3B3VExA6Qvg7yCNygzt8hE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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