SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9063083a3ee3470b8e4c7fcb98cbe3afdaccc309c76ed2c8698b64018d8a3545' 
  AND token = 'zZhXImb0MoTitM6K75j0QzsMwC0epDNkk0IkaRy/WOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}