SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76fedea0f58fb4b02d58ed3fffad683bd8426b947f025598ca994c4b6008b27a' 
  AND token = 'T9ezAJr4cYDokipx4dzGeAR0Up4OEIDEAw0Fm6xyh1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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