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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9bb9cac3c1e4bfe2ef0b79353018d703a25beb6490242bbc69643a5974c92bf0' 
  AND token = 'ljkEy3VZdNz5/emIQOF2e1zII/XD9NZdxbKZvGfa7EQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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