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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b420f1cc65d9db102d67b048a51039b6debaf31b7da0e1c344e6c277e47c6e06' 
  AND token = 'PHol6rGEe/Wcs1ZUf5Meo5+qvZGDaZB8LXRZCYm/IYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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