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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '452d65666fafb3627c53b932e388561f39b4dac917b2232416fdc9e871c97a66' 
  AND token = '/OOWcP7KLE6QErcQEuoAgLLnSSyqkUYBTnQMhwj4jtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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