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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd515a2c65abac5888d8e0eb1a4d3cfd0c778b1d17f1d7a2810a27df3b8b76d66' 
  AND token = 'kFOrci2PEU2YKhNUWPXKixm3XhvE8uUnp/k/lYjlc84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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