SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '256f5cbbc91ae563e3c5c375efc72197a2c9d8e220e0329cedb99d4211a3bc84' 
  AND token = 'BUqIv3jFvkznZ98Z/PjH+hslEWKbIXWsw02tVVg0V1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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