SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '205d1860732d2cf634aa852a90a2333487900ed195fca8e17422fd3b2cf2fc7b' 
  AND token = 'nYQ3W2BgVKAcswIMUZGqt3VAd9E29NjMF5suvPCham8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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