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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8203c8bb1efdcb2c6151104cefd273b5a7e9d5b52d3492bc353d20f5afa13d50' 
  AND token = 'TfX2OoXlbM4Xlx/kbhm0jZ4jVuzTec+Vs+BMMxFFIgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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