SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84a96bf07495a88b9e1d77ae4592d6d7e7eeb3c2ec3380dfa6ce33081ec6b80d' 
  AND token = 'MoiUJ89tl9FihFqrcFyM2/EyvcrFM/xAZIeDzO6Ci0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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