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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd609360ebde305bf38af0e6e49ff999c455d7db67f620dc1054c6a4b314325a1' 
  AND token = 'nwsdHbnofXJpymBKxEmDZLhDI2HCS7LdpuyCWLxEeKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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