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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '5b66d0f08e09bb4ddebe9dd1fcaef4a3eec6a6b4ff62e07ae2ca72800e410b69' 
  AND token = 'oV5JSySTTepJC72gSNLs2ESsIcbRyckQHDNmntsEBgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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