SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5dddfb44f13e2a4bdb26aa101d8aad13583181d5a9bd51041b25e6a9e2124f8' 
  AND token = 'rNDaoANY+Ta6g/BXBnOEXNg1iR1uh5N5glwmfKdFkNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}