SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80625e1c85e8c7e809630666a88bd2bcb40f3998580ee7889f238e7f818502a6' 
  AND token = '1DUK9/dbCce/vO8YpFvrPCFwxo2a7jKO+Jq6blNu4+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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