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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '87dd3105a5088aa9d4ce542fc4d7b214e2d4dfce73e234b01d5d3c3c87425b4b' 
  AND token = 'jEgLLfo5hb3L4HYe7iM5ab2C/wgIOSKj1rG4P/Ei/wc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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