SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6aebc86cf7e68276d79df5d8763f252b32cf24c8b259e7476d4f3b61e955024e' 
  AND token = 'AgUyTbYAQ6dLv8c1ybouBuRVugaH2bnbQCHNPcOUB54=' 
  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"
    }
  }
}