SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3744c9c83fcc772c63d9f9c2e2dfa74513d3e5714e5a881c2ceb29b7f38e041e' 
  AND token = 'KH8du6LwxOmxzVfa7HmLaIRn6+pmxH8NLjkpNHrD0uc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}