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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'dd2d69d2c2fd5d6a1aad2a0d89754a1ee2ef684daa6a7e0a9a5fc63b73d4e17a' 
  AND token = 'TaGHYbpBLIQCBbXUvs4JtmaoPSPaNMM3hMHqKtSv2BE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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