SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da6e1c065751dd2941059beda57843765aa5881c47960aabca3d2d65df667985' 
  AND token = 'LQ8V2HWgUWBTaxv8U8o8X9e5A9KfduDbUIJWWQRP+6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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