SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eeb6b2f9e95cc420b2324d8d0f2aa30c731bd7f4fb72f40be17125fc87ba8f7e' 
  AND token = 'eemnB7IxeMvKpIdxQXMhVqeabsD/hwdBizXHcZ85kM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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