SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fdeb01e06a6c49d9c01d3cc81d7cef97f9457749dda7f443d04a33562d883b5' 
  AND token = '+Bc3FZM8+PA6sD0heVuCvNhmEUwRNQjiG8Ldl8igDSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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