SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '335da4d43aaba8aac89b4afa70e2015745efa513927f0a233199bf4c0362d653' 
  AND token = 'ItGVXz2LPHh9/J8sosjdbhOlk1wprLdQDg7GFefkcAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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