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SELECT 
  design_data 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = '2E1P-L0XS-QYMU-7UL6-VI61-LIFR-UTRQ-AX4W' 
  AND product_id = 12 
  AND expires_at > 1777123767

Query time 0.00032

JSON explain

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