SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ffb09c799fe8cf5e1199c989e4d17b0f7e0ec704a6b32b28ff25c75b13fb582' 
  AND token = 'ZBwmudZmYx4fx+0TCf5OI+Zm3Caj9vLeTIClBlplhR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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