SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a46f0bd1e2153638b5d0484b6f246b9cb5b094e3488f5ccbf3a4c17639134292' 
  AND token = 'w/7VjZQxXX4p1DY7xDRYGxePInIbQkUyVLcRrjARJMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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