SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '001bb82bbc1bdf3657829877d75fc88b04cc83e05e4123cbdeb24d90cdaf9597' 
  AND token = 'gn7fnqXBixqAkTfONaPiYMfz0wjaIWIa3HCdGVtnK44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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