SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb231a678fe9d128c449e1ff9a8b571bc06dc9024dbf6a954a5e64a84bddf823' 
  AND token = 'rHP2P+BldoRJxO8wxGiSiOOkwP9D6CYZW+v+Fgq4vRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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