SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65e7cff43a849370c330c2261b54e5bd6a49ff048c17e798d57a7b45500cd700' 
  AND token = 'GJLwRR9ALz9QP9Yau2kHgVhCsdCbKBFch93fRN52rjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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