SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4968ac20b3c9778aa25d9c1159c021f4b02ed71c6ee8f3afca3cd6428667b4bd' 
  AND token = 'BTJ5ihRrdkfLGG2uBulm3ZLVGJemKG9vXYefpeMkCg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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