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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '995d31ba448e0e78f874a54344ea4cc344de11e8d084ed82108f2989c021b0a7' 
  AND token = 'vYueVNzfBvBlE5IyRCdO41xpsANbv0uqTVMOY/nZCUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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