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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8ddf333f8a47799de41b0dafb9c3839d2963f6357a48cdd532e1a3d4ff3c0a3' 
  AND token = 'eUYZ4QqvjAICqR2nWuSieOotdrMsXCwlPCoGdQtyy/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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