SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06ad5b28989667da48802c4bc8807d7beaf581ce6ee7d7d666764922cb685c47' 
  AND token = 'hn5A81LEXpayhsnR79007/fLTCAFvv5fsrWnhcI/aEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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