SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a183dd5f43de57f70d0a1d0ecdf9762398e203b6238feae6c27f7e6cc63fd070' 
  AND token = 'P79GzY0eIuV+hI+Kgo5vqJ48LRPHkrJYRLQLrPkqXMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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