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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'bd4e6cdd72772835949b79a0e76f9ba5f8297eb0fb65ffee2f2ceba5443eb111' 
  AND token = 'T/ZPIMq1vpcdBEw82yaHe8SM9Pz88pKnkP97KSWEmPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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