SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9207965e40830d67c0abff617bbc10bdfa3207bb4d73892fd86e5e8de3f726f3' 
  AND token = 'qB59ywTOrAFiexCIM3GqmtE7H9kZh2xprLz5jpWAv+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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