SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7f54c5c8b021fcf76ddafe9da2052d1c9533a58ba1abf72e61db6a9f3ca0937' 
  AND token = 'Wc0adA2kqHnjNBHEDiZWz2yiQBJnXhHMemzbkD69fuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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