SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0ae08de42a6cb61d19d978ada779e3cb5a31c42693c5407df0e45efb8354bd3' 
  AND token = '3z0YETqG71LYOG33sivzIMLKsvRc/ZxTseEDjWYZgFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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