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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c55d9e42a7d74217e89fc3c1aa1dc62e7dff942debd671c6c8a8a11fa5fc9a29' 
  AND token = 'twbiONmZHWpjhuDbqP61qYRdDasD+vLZG5Tg05Rq1X8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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