SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d83b2e7d11f3c91d094103bad886f8e96ee8589eec65f5cb01c57434a78bfe1' 
  AND token = 'F/VHx9qbgmLKw4+YRRCNfDGpUReyz7OveF2wkCnP6vs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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