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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5e848e306d2490d25294eb168e5d11ae27491ac653e1ec95db4aa68c959b5e3' 
  AND token = 'yzRVY4s/IPW3Mf/D/x2tVz5Ii6eJIw1b6KiITYR2NSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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