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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6b5e690830d8b9999d5ecc83bb6d83587c9ddfb171860e5c904eb29898a1a4e9' 
  AND token = '3ngfxt465J7LzlKavycNQdm39v+JY520VFCvSWjLAzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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