SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '954dd80db0401965feaf00c65024f3c4f0c14957f863e4158b50716a7d05ca9d' 
  AND token = 'b2+umuZ+5nujWx7gWJSTTKqOoOYxljMAyZW6d354p34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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