SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cea0a161f15e2ffabcd2c5d9cc8e626d8f614f982ce59a7783716c23fde2436' 
  AND token = 'pjwovYMnlvgSkRAcaUboFY+pBWvBeXr2hgqdwvG1738=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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