SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9ccd5aa9714f075451384ae6c7baade78d79facfbf2bfcbb15c4667aedabdfd' 
  AND token = '7L4l27nLkufNcuv8JgOjjzcGZCgNd+8iFOUCSjk8Kgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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